The present invention relates to a transmission valve control linkage and more particularly relates to a manually actuatable linkage for simultaneously effecting speed and direction control of a pair of reversible hydrostatic transmission units comprising final drive transmissions of a track-laying vehicle.
The simultaneous control of the speed and direction of rotation of hydrostatic transmission units is normally accomplished through valve means including a manually actuated valve element which is movable in opposite directions from a neutral position for respectively effecting opposite directions of rotation in the transmission units and for metering flow to the units such that their speed will increase as the element is increasingly displaced from its center position. Heretofore, the correct positioning of the valve element so as to effect a desired transmission condition has required the visual attention of the operator and this requirement for visual attention is not entirely satisfactory since the operator normally has other operations which also require his visual attention.